The development of the use of glass fiber waveguides to replace copper wires for carrying voice, data, or video signals in telecommunications systems is traced and described in an article entitled, "Photons in Fibers for Telecommunication" by Stewart E. Miller of Bell Telephone Laboratories which appeared beginning at page 1211 in the Mar. 18, 1977 issue of "Science" magazine, Vol. 195. A more complete discussion of this topic may be found in the book entitled, "Fundamentals of Optical Fiber Communications" which was edited by Michael K. Barnoski of the Hughes Research Laboratories and which was published by Academic Press of New York in 1976. Chapter 3 of this book deals with "Coupling Components for Optical Fiber Waveguides" and describes the requirements and problems inherent in such devices.
In the Miller article beginning at page 1211, the author states with reference to elementary fiber links that, "The optical portions of all such systems are similar and simple; they consist of a carrier generator (laser or LED), fiberguide cable, envelope detector "simple semiconductor-juncton (PIN) or avalanching photodiode], and conventional electronics to drive the carrier generator and to follow the detector. The information rate or bandwidth required on the link, in combination with the desired link length, lead to the choice between laser or LED and to selection of one of the fiber types described below.
Two slightly different kinds of glass are used for the core and the cladding of fibers, giving the core a slightly higher index of refraction than the cladding. The electromagneticwave modes guided in the core have fields that decay radially the cladding; with appropriate cladding thickness, very little influence on core modes is produced by the wave properties of the jacket or regions exterior to the jacket. Single-mode guidance is obtained with a core diameter of about 5 micrometers and an index difference between core and cladding of about 0.5 percent. Multimode fibers are necessary for carrying significant amounts of power from a LED; typical core diameters are in the 50- to 75-.mu.m range with an index difference of 1 or 2 percent."
Later at page 1213, in discussing fiber connectors and splicing, the author states,
"More new structures are required in fiberguide transmission systems to provide both permanent splices and fiberguide connections which can be disengaged. The background of theory can be summarized as follows: The requirement on transverse alignment of the fiber ends is about 0.2 core radius for approximately 0.2 db loss. For single-mode fibers, 0.2 core radius is about 1 .mu.m, a requirement that is likely to meet. For that reason, single-mode fibers are likely to be used only where the single-mode performance is essential.
Longitudinal end separation can be on the order of a core radius for about 0.1 db loss (with a bridging fluid or solid at the joint), so this requirement is not as critical as that for the transverse alignment, especially for multimode fibers where the core radius is about 25 .mu.m."
It can be seen from the above that transverse axial alignment of the two ends of a fiber to be joined in a connector is the most critical and difficult thing to achieve.
It is an object of the present invention to provide a simple, self-aligning one-piece molded connector for use with single or multi-mode optical fibers.
It is a further object of this invention to provide such a connector which is self-aligning and holds fibers securely in position axially.